diff --git a/.devcontainer/Dockerfile b/.devcontainer/Dockerfile
index 605d950..6b374cd 100644
--- a/.devcontainer/Dockerfile
+++ b/.devcontainer/Dockerfile
@@ -1,6 +1,11 @@
 FROM mcr.microsoft.com/devcontainers/base:ubuntu-24.04
 
 USER root
+RUN apt-get update && apt-get install -y locales && \
+    sed -i '/en_US.UTF-8/s/^# //g' /etc/locale.gen && \
+    locale-gen en_US.UTF-8
+ENV LANG=en_US.UTF-8 LC_ALL=en_US.UTF-8
+
 RUN curl -fsSL https://deb.nodesource.com/setup_lts.x | bash - && \
     apt-get install -y nodejs
 
diff --git a/test.sh b/test.sh
index f315783..16ac260 100755
--- a/test.sh
+++ b/test.sh
@@ -1,6 +1,5 @@
 #!/bin/bash
 set -e
-export ELIXIR_ERL_OPTIONS="+fnu"
 /home/vscode/.local/bin/mise trust /workspaces/firehose/mise.toml 2>/dev/null
 eval "$(/home/vscode/.local/bin/mise activate bash)"
 cd /workspaces/firehose/app